Chronometer-escapement.



No. 68|,006. Patented Aug. 20, I901.

J. F. THIN.

CIIBOIIOIETEII ESGAPEIEIT.

Amman m In. so, 1001.)

(In Nodal.)

UNITED STATES PATENT ()FEIoE.

JOIIAN F. TI-IIM, OF CHICAGO, ILLINOIS.

CHRONOM ETER-ESCAPEM ENT.

SPECIFICATION forming part of Letters Patent No. 681,006, dated August20, 1901.

Application filed March 20,1901. Serial No. 52,118. (No model.)

To CbZZ whom it may concern:

Be it known that I, J OHAN F. THIM, a citizen of the United States,residing at Chicago, in the county of Cook and State of Illinois, haveinvented certain new and useful Improvements in Chronometer-Escapements,of which the following, when taken in connection with the drawingsaccompanying and forming a part hereof, is a full and completedescription, sufficient to enable those skilled in the art to which itpertains to understand, make, and use the same.

This invention relates to and is an improvement upon thechronometer-escapement invented by Arnold and improved by Earnshaw andDent.

In the chronometer-escapement embodying this invention the operation issubstantially the same as in chronometer-escapements of the kind namedheretofore made. As the balance oscillates in the direction of the arrow1, Figure 1 of the drawings, its unlockingroller jewel comes in contactwith the secondary spring, (usually termed the gold spring or the goldunlocking-spring,) which is mounted on the detentspring (sometimescalled the spring-lever) of the escapement and presses or lifts thedetent-spring, so that its locking-jewel is freed from the tooth of theescape-wheel in contact therewith and the impulse-roller jewel receivesthe impact of another tooth of the escape-wheel and the balance receivesits impulse thereby. Further, as the balance returns its unlockingrollerjewel passes the secondary spring (the gold unlocking-spring) withoutmoving the detent spring, which rests against a stop, such secondaryspring being so pliable as to allow the unlocking-roller jewel to passfreely by it. The impulse is therefore in the escapement embodying thisinvention communicated from the escape-wheel direct to thebalance-arbor. It therefore occurs that in the escapement embodying myinvention, as well as in the ordinary escapement of the kind named, thestroke which moves the detent-spring withdraws the locking-jewel (ordetent) from the tooth of the escape-wheel, and at the same time thatthis tooth escapes another tooth of such escape-wheel strikes a pallet(the impulse-roller jewel) on the arbor of the balance and restores tothe balancewheel the force lost during a vibration.

In chronometer-escapements of the kind named as the same have beenheretofore constructed the blow from the tooth of the escape-wheel isreceived by the detent-spring striking the locking-jewel of suchdetentspring in a direction toward the blade or spring of suchdetent-spring and tends to compress or buckle such blade or springportion of such detent-spring, and,further, the escapewheel is not opento observation in the operation of the same; and the principal object ofthis invention is to so construct and combine the several partsconstituting the escapement that the blow received by the detent-springshall tend to subject the same to a tension strain, (andnot tocompression,) such blow being given in a direction from the blade orspring part of the detent-spring, and so tending to pull or stretch suchblade or spring part.

In the drawings accompanying and forming a part of this specificationand hereinbefore referred to, Fig. l is a top plan view of a portion ofthe upper plate of a chronometer with an escapement embodying thisinvention attached thereto, but with the balance and the impulse-rollerremoved from the arbor of the balance; Fig. 2, a vertical sectional viewon line 2 2 of Fig. 1 viewed in the direction indicated by the arrows;Fig. 3, a top plan view, on an enlarged scale, of the unlocking-rollerand jewel engaging with the gold unlocking-spring of the escapement andof the detent-spring with such parts in the same relative position asshown in Figs. 1 and 2; Fig. 4, a vertical sectional View on line 4 4 ofFig. 1, and Fig. 5 is a perspective view of the impulse-roller and theteeth of the escape-wheel.

A reference-letter applied to indicate a given part is used to designatesuch part throughout the several views wherever the same appears.

A is the upper plate of the chronometer,

having an escapement embodying this invention attached thereto. Plate Ais provided with a slot a, in which slot the detent-spring D,hereinafter described, is placed. Slot a is of sufficient width to admitof the necessary theop'eration thereof.

B is the balance-wheel of the chronometer,

and b is the arbor of such balance-wheel.

B is the potance of arbor?) and is attached to the under side of plate Aby screw 5 passing through bridge I)" of such potance and into, theplate.

B is the bridge of arbor 6 and is attached to the plate A by screw b 0is the escape-wheel of the chronometer.

O is a recess in the upper side of the up per plate A, in which recessthe escaperwheel O is placed.

C is the arbor of escape-Wheel O.

O is the escape-wheel bridge, and O is the screw bywhich the bridge isattached to the plate A.

D is the detent-spring of the escape-merit. The detent spring Dcomprisesthe-part d, by which such detent-spring is attached to theplate A, as by means-of'screw D, part 01?; forming a spring (i extendingfrom spring part 01 to curved part d and part d Curved part d extendsaround arbor b of the balancewheel 13. Parts (1 61 and d constitute thebody part. of the detent-spring D.

d isajewel or tooth mounted on part 01 of detent-spring D.

-E F are rollers on arbor b of balancewheel B.

e is a jewel or tooth on unlocking-r0ller E, and f is a jewel or toothon impulse-roller F. G is asecondary spring mounted on part d ofdetent-spring D, as byscrew g. Secondary spring G is ordinarily made ofgold and is termed in the art the gold spring of the es capement or theunlocking gold spring.

In the operation of this escape-ment one of the teethof the escape-wheelGpressesagainst the locking-jewel or pallet don detent-spring D, suchescape-wheel having at all times a tendency to. turn to the right, asisindicated by the arrow 2 in Fig. 1. Any one of the teeth of. theescape-wheelbeing in contact with thelocking-jewel at, whenthebal-ance-wheel B, unlocking-roller E, and impulse-roller F turn. inthe direction indicated by the arrow, Fig. 1, sothat the unlocking-jewele comes in contact with the gold unlocking-spring G,:

such unlocking-jewel or verge-tooth forces the detent-spring F backuntil the palletor locking-jewel d'isfree from engagement with suchtooth of the escapement-wheel, at which time the impulse-roller F onarborb is in position relative to the escape-wheel O,-so-that the jewelfrecei-ves an impulse from oneof the teeth of the escape-wheel which isadjacent theretov by the movement of the escape-wheel immediatelyfollowing the disengagement of the pallet or locking-jewel d fromthe-tooth of theescape-wheel incontact therewith. An impulse-is thus.given tobalance-wheel B in thedirection indicated by arrow 1:, and thisroller F is termed the impulse-roller. Asdetentsspring D is forced backor lifted by unlocking-jewel e in the manner above described immediatelyafter the locking-jewel d is released from engagement with the tooth ofthe escapement-whecl C, which is in con-' tact therewith, unlockingjewel passes around beyond the end of the gold unlockingspring G-because of the continued movement of the balance-wheel B and arbor I),and the detent-spring D is immediately returned to its initial positionby the resilience of spring part (1 thereof. Such return ofdetent-spring D is so quickly made that the pallet or look ing-J Qwel clreceives thereon the tooth of the scape-wheel O, succeeding the one lastreleased, as above described. On the return movement of thebalance-wheel B, arbor b, unlocking-roller E, and impulse-roller F goldunlocking-spring G- is so pliable that the unlocking-jewel e on roller Epasses by it withoutmoving the detentsp-ri-ng D, and the escape-wheel Ois then in such position relative to impulse roller F-and theimpulse-jewel f thereon that such impulse-jewel passes betweenthe teethof the escape-wheel adjacent thereto without coming in contacttherewith. Theoperation of the escapement is, i-twill be observed,substantiallythesame as theoperation of like escapements of this classas heretofore made, except that the impact recei ved by'the pallet orlocking-jewel d in the i escapement embodying my invention producestension on spring part 01 of the detent spring, and not compression,as-is done in the escapemen-ts of this kind heretofore made. Hence I amableto-make such spring part d thinner than the same has heretofore beenmade. Further, it will be observed that the fulcrum on whichthe--detent-spring turn-s that is, spring (1 of detent-spring Dis onthesame side of the locking-jewel d as is'the arbor b, which constitutesthe fulcrum of the unlockingjewel e, and henceengagement of 'theunlocking jewel ewi-th gold spring G is less so farasslippage isconcerned, and less friction is obtained than is as the'samehave beenheretofore constructed, while inthe return movement of theunlocking-jewel the fulcrum of the unlocked gold springGis-substantial-lyinthe same relation to the fulcrum of suchunlockingjewel as in the escapements heretofore constructed, and a quickerreleas-- ing of the-engagement between theunlockingjewel and thegoldspring-in the return movement of the unlocking-jewelis obtained.

Having thus described myinvention audits operation, what I claim asnew,and desire to secure byLetters Patent of the United States, 1s-

1. Ina chro-nometer-escapement, a detentspringprovided with aspringportion adjacent to theend thereof arranged to be attached tothe'plateof the-ch-ronometcr, means for securing a secondary spring to-the freeend of' the detent-spring, a curved portion, i arranged toextend aroundthe balance-arbor iof the chronometer, between the spring porltion ofthe detent-spring and the point of attachment of the secondary springthereto,

a locking-j ewel mounted on the detent-spring between the curved portionthereof and the point of attachment of the secondary spring thereto, anda secondary spring attached at one end thereof to the free end of thedetentspring; substantially as described.

2. A detent-spring comprising a part arranged to be attached to a plateof a chronometer, a spring portion adjacent to such attachable part, acurved part arranged to extend around a balance-arbor and a body partarranged to have attached thereto a locking-jewel for an escape-wheeland a secondary spring for an unlocking-jewel, in combination with asecondary springattached at one end thereof to the free end of thedetent-spring and extending to the curved portion of such detent-spring,and a lockingjewel, whereby when an unlocking-jewel, of an escapementwhereof the detent-spring, the locking-jewel and the secondary springare elements, lifts the secondary spring in one direction, carryingtherewith the detent-sprin g, the fulcrum of such secondary spring is atthe spring end of the detent-sprin g, and when such unlocking jewellifts the secondary spring in the other direction the fulcrum of thesecondary spring is at the other end of the detent-spring; substantiallyas described.

3. In a chronometer-escapement, a detentspring, attachable at one end toa chronometer-plate and provided with a spring portion adjacent to theattachable end and a body part adjacent to the spring portion, theattachable portion, the spring portion and the body portion of thespring being integral, in combination with a locking-jewel mounted onthe body portion of the detent-spring for an escape-wheel, and asecondary spring attached at one end thereof to the free end of thedetent-spring, the secondary spring extending along the detent-spring sothat the end thereof operated on by the unlockingjewel of theescapernent is between the locking-jewel and the spring portion of thededent-spring; substantially as described.

J OHAN F. THIM. \Vitnesses:

CHARLES TURNER BROWN, CORA A. ADAMS.

